1. Field of the Invention
This invention relates to an electron beam emitting device and an image displaying device using an electron beam emitting device and more particularly to a thin type electron beam emitting device or an image displaying device using a surface conduction type of thin film device or an electron emitting device similar thereto.
2. Related Background Art
In recent years, in the field of information equipment or TV receivers for domestic use, a thin type image displaying device with good visual recognition has been demanded. In the prior art, thin type image displaying devices such as a liquid crystal displaying device, an EL displaying device, a plasma display panel, etc., have been developed. However, these devices have problems relating to the visual angle, color formation, luminosity, etc. As a result they cannot be said to satisfy the performance standards quality demanded by the market.
In addition, in the prior art, devices capable of obtaining emission of electrons with a simple structure, there have been developed, for example, the cold cathode-ray device reported by M. I. Elinson [Radio Eng. Electron. Phys. vol. 10, 1290-1296, 1965]. This device utilizes the phenomenon that electron emission occurs by passing current through a thin film with small area formed on a substrate in parallel to the thin surface, and is generally called the surface conduction type of thin film device.
Examples of such surface conduction type of thin film device include the one using a SnO.sub.2 (Sb) thin film developed by Elinson et al as mentioned above; one using an Au thin film [G. Dittmer: "Thin Solid Films", vol. 9, p. 317, 1972]; one using an ITO film [M. Harwell and C. G. Fonstad: "IEEE Trans. ED Conf.", p. 519, 1975]; and one using a carbon thin film [Hisashi Araki et al: "Vacuum", vol. 26, No. 1, p. 22, 1983].
These surface conduction type devices have the following advantages:
1) High electron emitting efficiency can be obtained. PA1 2) Their simple structure affords easy production. PA1 3) A large number of devices can be formed (multi-formation) on the same substrate.
Accordingly, if these surface conduction type of thin film devices can be utilized as the electron generating source for a flat plate type CRT image displaying device, an image displaying device having a better visual angle, having better color formation and luminosity and having lower consumption power, etc. than a flat plate type CRT displaying device can be provided.
However, when a surface conduction type of thin film device is utilized as an electron generating source of an image displaying device, if the same number of surface conduction type of thin film devices are provided as the number of displaying picture elements for excitation of phosphor, the number of the devices will become enormous, whereby the production yield will be lowered thereby resulting in increased cost. On the other hand, if the whole image surface is scanned by use of a single device, the structure of the device will become complicated as in the case of the CRT of the prior art, whereby it is impossible to realize thinning of the device.
Accordingly, as a compromise, if some picture elements to some 10 picture elements are allocated for one device, it becomes possible to ballance both the production yield of the device and thinning of the device at a high level. However, even in that case, for scanning of an electron beam, deflectors are required to be equipped for each device, and yet the deflector of the prior art had a complicated electrode shape as shown in FIG. 7. Therefore, it has been difficult to make the device thin or to constitute them in multiple forms. In the Figure, 71 encircled with a dotted line shows one device of the surface conduction type discharging device, 72 encircled similarly with a dotted line shows one deflector, 73 denotes one picture element of an emitting member and 74 denotes a glass plate.